This report summarizes the clinical frequencies of systemic hypertension and necropsy evidence of cardiomegaly in various cardiovascular conditions. Systemic hypertension is present in greater than 50% of patients with various coronary events, in greater than 75% of patients with various cerebrovascular events, and in greater than 90% of patients with aortic dissection. Hypertension is the sole underlying factor in most patients with nontraumatic cerebral arterial or aortic (dissection = partial rupture) rupture. In association with hypercholesterolemia (serum total cholesterolemia greater than 150 mg/dl), hypertension clearly accelerates atherosclerosis and its devastating consequences.